Oft-injured Raiders running back Darren McFadden was lost in the first half with a hamstring injury. His return was initially ruled questionable but he returned from the halftime locker room in street clothes and was later ruled out.
The Raiders also lost Pro Bowl fullback Marcel Reece to a knee injury in the first half and, with quarterback Terrelle Pryor inactive after suffering a concussion Monday, Oakland was playing without its starting offensive backfield.
McFadden, who is in a contract year, has never played more than 13 games in a season. He had 29 yards rushing on five carries.
The Raiders jumped out to a 14-0 lead before Washington crept back to within 14-10 using the no-huddle offense.